In a semiconductor power converter, a voltage-controlled power device such as an Insulated Gate Bipolar Transistor (IGBT) or a power MOSFET is used, and an inverter is configured with a drive circuit for driving these power devices. Drawbacks caused when driving the power devices are losses, noises, and their temperature characteristics at the time of turning them on.
To reduce the losses, noises and temperature dependences at the time turning on the power devices, there are proposals of, for example, the drive circuit of an insulated gate type device disclosed in Patent Literature 1 and the drive circuit of a power transistor disclosed in Patent Literature 2.
In a conventional example disclosed in the Patent Literature 1, the gate of the insulated gate type device is connected to the power supply potential side through the constant current source at the time of turning on the voltage-controlled device, and the gate of the insulated gate type device is connected to the emitter side at the time of turning it off.
In a conventional example disclosed in Patent Literature 2, other than the configuration disclosed in Patent Literature 1, a zener diode for detecting the temperature of the power transistor to which the constant current has been supplied from the constant current source is provided, so that a voltage output corresponding to the temperature of the power transistor output from the anode of the zener diode for detecting the temperature is fed back to a current controller of controlling the constant current of the constant current source.